Integrated InP Arbitrary Waveform Generation and Detection for THzGeneration and Detection for THz

Advanced Format Trx and RcvS J Ben YooS. J. Ben Yoo

UC Davis yoo@ece.ucdavis.eduAcknowledgements:c o edge e ts

E. Ippen, F. Kaertner, L. Koldzijeski (MIT)J. P. Heritage, K. Okamoto, A-V Pham, R. Scott, F.Soares, J-H Baek,

X Zh N F t i D G i l S Ch A K l R Y (UCD i )X.Zhou, N. Fontaine, D. Geisler, S. Cheung, A. Kalarar, R. Yu (UCDavis)W.Tsang, K-Y Liou, G. Chu, R.Hamm, H.Huo, et al (Multiplex)

S. Lourdudoss, C.Junesand, F. Olsson, et al (KTH)S. Lourdudoss, C.Junesand, F. Olsson, et al (KTH)K. Nary, R.Coccioli, R.Johnson, N. Yeung, et al (Inphi)

1ECOC 2009

This work was supported in part by DARPA DSO and SPAWAR under OAWG contract HR0011-05-C-0155

Serial vs. Parallel 100 G technology 100G serial transport

lase

rla

ser

aser

aser

ser

ser

er r r

100G parallel transport (OTN VCAT)

(b)

l la las

las

lase

lase

lase

rla

ser

(b)

•Use single wavelength (can be multi-level)

• Use multiple wavelengths & modulators

• Needs 100 G (or 2x50G) electronics• Better spectral efficiency but more sensitive to dispersion and

• Needs 10 G electronics with possible synchronization• Manageable dispersion and PMD but poorer spectral

Slide_2

S. J. B. Yoo

PMD efficiency

Scalable Optical Arbitrary Waveform Generation

0 0 0 0

Intensity (au)

0 0 0 0

Intensity (au)

0 0 0 0

Intensity (au)

0 0 0 0

Intensity (au)

AM PMAM PM

MU

X MU -300 -200 -100 0 100 200 300

0

0.5

1

Inte

nsity

(au)

-300 -200 -100 0 100 200 300

Pha

se (1

rad/

div)

Optical Comb

-500

500

0.2

0.4

0.6

0.8 1

Frequency (G

Hz)

-500

500

0.2

0.4

0.6

0.8 1

Frequency (G

Hz)

-500

500

0.2

0.4

0.6

0.8 1

Frequency (G

Hz)

-500

500

0.2

0.4

0.6

0.8 1

Frequency (G

Hz)

-500

50-3 -2 -1 0 1 2 3

AM PM

DEM

UX Time (ps)Time (ps)

Generator

3 2

Phase (rad)

3• At a glance, this is useful for parallel 40G/100G Trx/Rcv with independent ASK,

PSK, DPSK, QPSK, DQPSK, etc.

Optical Arbitrary Waveform GenerationParallel GHz Rate Intensity and Phase Modulation

Bandwidth Scalable

Am

Bandwidth-Scalable

THz Rate Optical Arbitrary Waveform

Am

Am

Am

Spectral

Am

SpectralSpectral Demultiplexer

Spectral Multiplexer

• Fourier Synthesis of Arbitrary Waveforms scaling to Terahertz BW

• Optical arbitrary waveform generation with high-speed modulation

• Tradeoff between wide-optical-bandwidth and electrical-bandwidth

• High-resolution AWGs can offer high-capacity signal processing systems based on low bandwidth electronics (< 10GHz)

4systems based on low bandwidth electronics (< 10GHz)

• Monolithic InP construction in support of high-speed modulation

Optical Arbitrary Waveform Generation Time/Frequency

a.u.

)

ad)

Duration or Record Length

Temporal Resolution

Temporal Domain

Inte

nsity

(a

Pha

se (r

aTemporal Resolution

Fourier TransformSpectral Domain

Inverse Fourier Transform

dB/d

iv)

(rad

)

Spectral Domain

Spectral Resolution

Bandwidth

nten

sity

(5

Pha

se (

In

5CLEO 2009

Packaged InP OAWG(10 Ch AM+ 10 Ch PM) x 10 GHz( )

AM-PM modulation board

6

OAWG: TW-EAEA pitch=150um

BCB opening = 3um

NbufferGND

BCB

Active

Nbuffer

Waveguide 11 W =3+1um Wvia = 20ummesa = 11um W =3+1um Wvia =

14umBCB on mesa etch stop

GND

•NiCr resistor 200um

•TL: sig-gnd-gap: 15-30-7

•TL: sig-gnd-gap: 15-30-11.5um•EA Length = 300um

•TL: sig-gnd-gap: 6-20-15um

OAWG-TW-PMTW PMTW-PM

pitch=150um

SI

Nbuffer edge mesa

edge

SI

GND

NbufferBCB

Length = 2000um

BCB on mesa etch stop

BCB on Nbuffer

4um

Wvia 14um Lion = 8um

Lbcb

BCB on mesa etch stop

P i d

4um

Wmesa 11um

BCB opening 3um Wion =

16um

Lbcb = 10um

W 3+1u

m

Period = 32um

8sig-gnd-gap: 6-20-

15um

10 Channel AM-PM modulation board

9

40ch-100GHz Si-AWG die

Measured transmission spectrumMeasured transmission spectrum

40 ch x 100 GHz

10 GHz X 64 Channel Silica Folded OAWG

12

40 GHz x 128 channel (~5 THz) OAWG W f Sh T i iOAWG Waveform Shaper Transmission

10

0

B) 2

d)

-20

-10

Inte

nsity

(dB

2

0

Phas

e (r

ad

1525 1530 1535 1540 1545 1550 1555 1560 1565-30

Wavelength (nm)1525 1530 1535 1540 1545 1550 1555 1560 1565

-2Optical FrequencyComb

Wavelength (nm)

13

AM/PM Optical Comb Generation

er (d

B)

-5

0

Dual-Electrode MZM with controlled phase and amplitude modulation for a maximally flat comb line generation. tiv

e P

owe

-15

-10

Dual-Electrode

Amplifier Rel

at

-25

-20

RF1

Polarization

Dual Electrode Mach-Zehnder

Modulator

Single Frequency

LaserMeasurements

Delay Line

0 dBm -14 dBm Wavelength (nm)1548 1549 1550 1551 1552 1553 1554

RF2 Bias

o a at oController

Laser

Microwave

Bias Voltage

/2

20 GHz

Ref. T. Sakamoto, et al, Optics Letters, Vol. 32, No.11, pp. 1515-1517

SynthesizerPower Splitter Amplifier14

175 –line Transform-Limited Optical Frequency C bComb

15

Target Pulse ( )(0-pi Pulse A)

1 I i 3

Ph

1 I i

3 Ph

0.7

0.8

0.9Intensity

1

2

3Phase

0.7

0.8

0.9Intensity

1

2

Phase

0.4

0.5

0.6

Inte

nsity

(a.u

.)

-1

0

1

Pha

se (r

ads)

0.4

0.5

0.6

Inte

nsity

(a.u

.)

1

0

1

Phas

e (ra

ds)

0.1

0.2

0.3

-3

-2

-1

0.1

0.2

0.3

3

-2

-1

-50 0 500

Frequency (GHz)

-3

-20 -10 0 10 20

0

Time (ps)

-3

16

Comparison of Final Shapings

) )Target = grayty

(au)

1 ra

d/di

v

ty (a

u)

1 ra

d/di

v

Inte

nsit

Phas

e (1

Inte

nsit

Phas

e (1

-10 0 10Time (ps)

-10 0 10 -10 0 10Time (ps)

-10 0 10

Similar waveform shaping errors result in a larger G’ for spread waveforms

17

OAWG Shaped Pulse --unchirpedTransform Limited Pulse with Super Gaussian Spectral Amplitude

3

0 8

1

IntensityTarget

0 8

1

IntensityTarget

1

2

3PhaseTarget

0 8

1

IntensityTarget

2

3

4PhaseTarget

0.6

0.8

nten

sity

(a.u

.)

0.6

0.8

nten

sity

(a.u

.)

1

0

1

Pha

se (r

ads)

0.6

0.8

nten

sity

(a.u

.)

0

1

2

Pha

se (r

ads)

0.2

0.4In

0.2

0.4In

-2

-1 P

0.2

0.4In-2

-1

P

-200 0 2000

Frequency (GHz)

-200 0 200

0

Frequency (GHz)

-3 -20 -10 0 10 20

0

Time (ps)

-3

* Super Gaussian is of the form:18 Super Gaussian is of the form:

OAWG Shaped Pulse --chirpedSuper Gaussian* Spectral Amplitude with Purely Quadratic Spectral Phase

24 Radians over 500 GHz24 Radians over 500 GHz

Intensity

12 Phase

Intensity 0

Phase

0.8

1

u.)

yTarget

8

10

s)

Target

0.8

1

u.)

IntensityTarget

-5

0

s)

PhaseTarget

0.4

0.6

Inte

nsity

(a.

4

6

Pha

se (r

ad

0.4

0.6

Inte

nsity

(a.u

-15

-10

Pha

se (r

ads

0

0.2

0

2

0

0.2 -20

-200 0 2000

Frequency (GHz)

-20 -10 0 10 20

0

Time (ps)

* Super Gaussian is of the form:

Click button to run movie, click “yes” on the warning

dialog Super Gaussian is of the form: 19

dialog.

10 chx10 Gb/s OAWG experiment

20

Generated Waveforms from InP OAWG encoder

Fig.a 0V Fig.b 2.5V Fig.e 10V

Fig.c 5V Fig d 7 5V21

Fig.c 5VTime 20 ps/divFig.d 7.5V

100 Channel Reflective-Type 100 channel OAWG 2.9 cm

Reflective OAWG

3.5 cm

Reflective OAWG device with Reflective

AWG

Reflective OAWG device with Full AWG

mode filters

4 MMI i t/ t t (t

23

4 MMI input/output (to differentiate input from

output)

23angled input- and output

waveguides mode filters 2 straight input/output

Optically Interconnected OAWG Michelson InterferometerSOAs or EAsSOAs or EAs

IProbe in V1Pump 1

Probe out V2Pump 2

12 101AWG

• Guaranteed DEMUX-MUX

alignment

• Low loss optical

1Michelson

• Low loss optical pump coupling

• Independent amplitude and

110

pphase control

• Short optical active device (< 1

mm) to achieve > 1024 RF wave mm) to achieve > 10 GHz bandwidth

Fabricated 100ch x 10 GHz OAWG encoder deviceFabricated 100ch x 10 GHz OAWG encoder deviceMask Layout Photograph of Fabricated Device

(after metalization)( )

Measured AWG Transmission After Phase-Error Correction(100 channel measurement)(100 channel measurement)

-0

-5

-10

-15

1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562-20

Wavelength (nm)

26

1310 nm Interconnection Lasers

012345

Frequency Response

HY6340

HY5640

(TEC)

8-7-6-5-4-3-2-10

espo

nse

(dB) 70mA

80mA90mA

HY6340

Current driver

-15-14-13-12-11-10-9-8

Freq

uenc

y R

e0 1 2 3 4 5 6 7 8 9 10

-20-19-18-17-1615

Frequency (GHz)

Frequency (GHz)

• 40~60 lasers (4~6 boards) drivers with 10 GHz response

100 ch x 10 GHz OAWG with Optical-interconnect

27 • Third vendor analog drivers

• PRBS Port Duplicator x 3

OAWG based 100 G~1Tb/s Transmission with ~10 G electronics

0 0 0 0

Intensity (au)

0 0 0 0

Intensity (au)

0 0 0 0

Intensity (au)

0 0 0 0

Intensity (au)

AM PMAM PM

MU

X MU -300 -200 -100 0 100 200 300

0

0.5

1

Inte

nsity

(au)

-300 -200 -100 0 100 200 300

Pha

se (1

rad/

div)

Optical Comb

-500

500

0.2

0.4

0.6

0.8 1

Frequency (G

Hz)

-500

500

0.2

0.4

0.6

0.8 1

Frequency (G

Hz)

-500

500

0.2

0.4

0.6

0.8 1

Frequency (G

Hz)

-500

500

0.2

0.4

0.6

0.8 1

Frequency (G

Hz)

-500

50-3 -2 -1 0 1 2 3

AM PM

DEM

UX Time (ps)Time (ps)

Generator

3 2

Phase (rad)

28• At a glance, this is useful for parallel 40G/100G Trx/Rcv with independent ASK,

PSK, DPSK, QPSK, DQPSK, etc.

360 Gb/s PRBS Data OOK & DPSK ( i t)(experiment)

OO

KK

DPS

K

29

Predistorted 360 Gb/s 10 km Single Mode Fiber T i i R ltTransmission Results

OO

KK

DPS

K

30

400 Gb/s NRZ-OOK PRBS generation 1 bit/s-Hz

400 Gb/s NRZ-OOK PRBS generation (40-bit-length) (a) Spectral domain (blue) intensity and (red) phase targets indicated by ‘x’. (b) Time-domain optical field (blue) intensity and (red) phase. Target packet indicated by lighter shades. (c) Target and (d) measured eye

diagrams.diagrams.

31

1.2 Tb/s NRZ-16QAM PRBS with 3 bit/s-Hz

120 bit 1200 Gb/s NRZ-QAM packet (a) spectral intensity (blue) and phase (red), and (b) optical field (blue) intensity, (red) phase. Target indicated by lighter shades and

‘x’. (c) Target and (d) measured constellation diagrams.

32

Optical Arbitrary Waveform MeasurementsOptical Arbitrary Waveform Measurements

• Spectral slices of the signal (S) are coherently detected using a 90°optical hybrid circuit (OHC) and a single mode from the LO OFC

• Fast photodiodes (bandwidth>spectral slice width) measure the four OHC outputs

• Post processing reconstructs signal from measured outputs33

g g

Schematic Configuration of the Single-Shot O ti l A bit W f M tOptical Arbitrary Waveform Measurement

N. K. Fontaine, R. P. Scott, C. Yang, J. P. Heritage, and S. J. B. Yoo, "Near Quantum-Limited Single-Shot Full-Field Measurements of Arbitrarily Shaped Optical Waveforms," acceptedSingle Shot Full Field Measurements of Arbitrarily Shaped Optical Waveforms, accepted for publication in Conference on Lasers and Electro-Optics (CLEO 2009), Paper CThDD7,

2009.

Single-Shot OAWM: 500 photons (64.1 aJ)St ti ti f 200 h t ( i d t 20 H )Statistics for 200 shots (acquired at 20 Hz)

ad)At least ½ of noise

shown is due to

100

0 G

Hz

0

Phas

e (r

a

IntensityMax

Min±

shown is due to shot noise

−150 −100 −50 0 50 100 1500

50

Phot

ons/

1

Frequency (GHz)

Phase

For comparison records

0

Phas

e (r

ad)

For comparison, records

for repetitive waveforms:Autocorrelation

0

50

100

150

Phot

ons/

ps

Phase

IntensityMax

Min±

52 aJ

SHG FROG

124 aJ

−100 −80 −60 −40 −20 0 20 40 60 80 1000

Time (ps)

500 Gb/s 50-bit duobinary PRBS measurements using a bandwidth of 490 GHzg

36

Photonic Integrated Transceivers for Advanced Modulation FormatsModulation Formats

• THz scale Trx and Rcv– Serial modulation schemes will be limited in capacity

WDM combination will limit spectral efficiency– WDM combination will limit spectral efficiency– OAWG/OAWM schemes will allow THz and beyond

scaleability with full support of any modulation format of any shape & any multiplexing schemes (e.g. CO-OFDM, CO-WDM, p y p g ( g , ,etc)

• OAWG/OAWM– Energy-efficient low frequency electronics (e.g. 10 GHz)Energy efficient low frequency electronics (e.g. 10 GHz)– Coherent optical synthesis to scale up to THz and beyond– Supports any format/protocol incl. OFDM, CO-OFDM, CO-

WDM,,– Resiliency against failures of modulators or drivers.– Monolithic and Hybrid integration possible– Benefits from quantum limited detection in amplitude/phaseBenefits from quantum limited detection in amplitude/phase

37

Single-Shot OAWM: 40,000 photons (5.1 pJ)St ti ti f 200 h t ( i d t 20 H )Statistics for 200 shots (acquired at 20 Hz)

3000

4000

GH

z

0

Phas

e (r

ad)

IntensityMax

Min±

−150 −100 −50 0 50 100 1500

1000

2000

3000

Phot

ons/

10 G

PhaseMin

Frequency (GHz)

0

hase

(rad

)

3000

6000

9000

Phot

ons/

ps

Ph

Phase

IntensityMax

Min±

0

3000P

−100 −80 −60 −40 −20 0 20 40 60 80 100Time (ps)

Optical Arbitrary Waveform Generation

Terascale O G LIDAR li ti Terabit/sec communication

1

IntensityTarget

-5

0

PhaseTarget

1

IntensityTarget

3

4

PhaseTarget 1

IntensityTarget

3

4

PhaseTarget

OAWG LIDAR applications ~Terabit/sec communication

0.4

0.6

0.8

Inte

nsity

(a.u

.)

-15

-10

Pha

se (r

ads)

0.4

0.6

0.8

Inte

nsity

(a.u

.)

0

1

2

Pha

se (r

ads)

0.4

0.6

0.8

Inte

nsity

(a.u

.)

0

1

2

Phas

e (ra

ds)

-20 -10 0 10 200

0.2

-20

-20 -10 0 10 20

0

0.2

0.4

-3

-2

-1

-20 -10 0 10 200

0.2

Time (ps)

-3

-2

-1

Time (ps)

* Super Gaussian is of the form: Time (ps)

Time (ps)

39

Example of FQSI Dynamic Range• Correctly retrieves 180 Gb/s bit-sequence with >20 dB variation in spectruma p e o QS y a c a ge• Signal spectrum has a strong peak (20,000 photons/10 GHz, f = 0 GHz) which

is greater than R(ω) (9,000 photons/10 GHz), yet weaker than R(ω) across the rest of the bandwidth (1,000 photons/10 GHz)

40CLEO 2009

Chirped Pulse MeasurementC ped u se easu e e t

41

Propagation over 25 km SMF

42

Various Measurements

Various single-shot FQSI measured waveforms

• Demonstrated near quantum-limited, single-shot full-field measurements using four-quadrature spectral interferometry (FQSI) with a 20 Hz update rate

• 500 GHz optical bandwidth (2 ps resolution), 200 ps record lengthp ( p ), p g

• Single-shot measurements of 150 aJ (1,200 photons) waveforms<

Optical Arbitrary Waveform Generation (OAWG) Encoder p y ( )

• Fourier Synthesis of Arbitrary Waveforms scaling to Terahertz BW• Fourier Synthesis of Arbitrary Waveforms scaling to Terahertz BW

• Optical arbitrary waveform generation with high-speed modulation

• Tradeoff between wide-optical-bandwidth and electrical-bandwidth

• High-resolution AWGs can offer high-capacity signal processing systems based on low bandwidth electronics (< 10GHz)

• Monolithic InP construction in support of high-speed modulationMonolithic InP construction in support of high speed modulation44

Fabricated 5 GHz AWG with segmented tapering

Ultrahigh Density AWG (5 GHz)

10EO phase shifters

-14

-12

-10ch1 ch32FSR

B)

-18

-16

()

sion

(dB

iber

-24

-22

-20

ansm

iss

ber-

to-F

-28

-26

-24

Tra

Fib

Segmented

transition

1550 1550.5 1551 1551.5-30

Wavelength (nm)• Photonic crystal-like segmented taper used for loss reduction

transition region[1]

y g p• High optical resolution to accommodate lower speed electronic

with better power efficiency

[1] Y. P. Li, US Patent No. 5,745,618 (1998).

46

Static OAWG– Integrated Fourier Domain line-by-line Pulse shaping

•Static or DC phase and amplitude modulation p pPhase Modulators Intensity Modulators

Spectral Multiplexer

Spectral Deultiplexer

Input Optical Frequency

Comb

Shaped Optical Frequency

Comb

Shape an Optical Full control of

waveform within 1 periodFrequency Inverse Fourier

Transform

period

Frequency Domain Time Domain48

CLEO 2009

200-Fiber Fan-In Silica PLC

Channel # Measured power at PD [dBm]18 8.230 8.150 8.465 8.0

Alligned PM fiber Array on Silicon V‐

80 8.096 8.1

106 8.0127 8.2140 7.9

on Silicon V‐Groove

EDFA PCANDevices200‐Fiber Silica PLC

PD

camera

BS169 8.2199 8.5

Average Loss of Fan‐In camera

Pin=12.5dBm

Array= 1.4 dB =12.5dBm (Pin)‐8.1dBm 

(average output)‐3dB(from beam splitter)

49

Symmetry in Optical Arbitrary Waveform Generation and Measurement

(a) Optical arbitrary waveform generation

(b) Nested Mach-Zehnder modulator for modulating the real and imaginary part (I and Q) of the field(I and Q) of the field

(c) Optical arbitrary waveform measurement

(d) Four-quadrature balanced homodyne coherent detection to measure I and Q

Measurement setupBERT

(pattern generation)Inphi Test

Pattern

RF SynthesizerGenerator

RF driving signals (500mVpp)Inphi Test Inphi Test RF driving signals (500mVpp)Inphi Test Pattern

Generator

Inphi Test Pattern

Generator

10 GHz Optical 10 GHz InP OAWGEDFA 65 GHz DCA

10 pairs of signal driving 10 (AM, PM)

Comb Board

DC bi

EDFA 65 GHz DCA

51DC reverse bias

DC bias on drivers

Target Pulse #3 ( )(0-pi Pulse B)

1 1 3

0.7

0.8

0.9Intensity

2

3Phase

0.7

0.8

0.9Intensity

2

3Phase

0.4

0.5

0.6

Inte

nsity

(a.u

.)

0

1

Pha

se (r

ads)

0.4

0.5

0.6

Inte

nsity

(a.u

.)

0

1

Pha

se (r

ads)

0.1

0.2

0.3

-2

-1

0.1

0.2

0.3

-2

-1

-50 0 500

Frequency (GHz)

-3

-20 -10 0 10 20

0

Time (ps)

-3

52

Measured Pulse #3( )(0-pi Pulse B)

1 1

0.7

0.8

0.9

1Intensity

2

3Phase

0.7

0.8

0.9

1Intensity

2

3Phase

0.4

0.5

0.6

Inte

nsity

(a.u

.)

0

1

Pha

se (r

ads)

0.4

0.5

0.6

Inte

nsity

(a.u

.)

0

1

Pha

se (r

ads)

0.1

0.2

0.3

-2

-1

0.1

0.2

0.3

-2

-1

-50 0 500

Frequency (GHz)

-3

-20 -10 0 10 20

0

Time (ps)

-3

53

FROG ERROR measurement for Pulse #3 (0-pi Pulse B)

MeasuredTarget

100

0 7

0.8

0.9

100

0 7

0.8

0.9

g

uenc

y (G

Hz)

0

50

0 4

0.5

0.6

0.7

uenc

y (G

Hz)

0

50

0 4

0.5

0.6

0.7

frequ

-50

0.2

0.3

0.4

frequ

-50

0.2

0.3

0.4

time (ps)

-20 -10 0 10 20

-100

0

0.1

time (ps)

-20 -10 0 10 20

-100

0

0.1

G = 0 002554

G = 0.0025

G’ = 5%

OAWM PLC and Fan-In PLC

OAWM PLC

Fan-In PLC

55